JP7108907B2 - Bonding material, method for manufacturing semiconductor device using bonding material, and semiconductor device - Google Patents

Description

The present invention provides a bonding material that can be connected to a heat spreader, a heat sink, or the like in order to cool a semiconductor such as gallium nitride that generates a large amount of heat, a semiconductor device that uses the bonding material, and a semiconductor device that uses the bonding material. and a manufacturing method of

Gallium nitride, a compound semiconductor, is widely used as a high-brightness light-emitting device. Light-emitting diodes (LEDs) using gallium nitride have advantages over incandescent lamps, such as long life, low power consumption, high-speed response, and space-saving, and are rapidly becoming popular. In order to further increase the brightness, it is preferable to increase the driving current, but the amount of heat generated by the light emitting element increases, and a cooling mechanism is required. Therefore, the light-emitting element is adhered or bonded to a base with good heat dissipation using a heat-dissipating sheet, silver paste, or solder alloy (see, for example, Patent Document 1).

FIG. 3 is a schematic diagram of a conventional semiconductor device 301. As shown in FIG. The light emitting element 302 is adhered to a copper alloy base 303 having thermal conductivity using a silver paste 304 . An electrode 305 is formed on the surface of the base 303 , and the light emitting element 302 and the electrode 305 are electrically connected by a wire 306 . The periphery of the light emitting element 302 and the wire 306 is sealed with a sealing resin 307 .
In other words, in the conventional semiconductor device 301, the light-emitting element 302 is adhered to the base 303 with the silver paste 304 to which silver having high thermal conductivity is added as a filler, so that the heat generated from the light-emitting element 302 is efficiently transferred to the base. I'm escaping to 303.

JP 2004-265986 A

In general, silver paste has a thermal conductivity of about 30 w/m·K, and copper alloy has a thermal conductivity of about 400 W/m·K. When the silver paste described in Patent Document 1 is used to bond to a copper alloy base, the thermal conductivity of the silver paste is not so high. There is a problem that the temperature rises and the luminous efficiency decreases.

In addition, the use of silver paste poses the problem that after the reliability test, cracks occur at the interface due to silver migration, sulfurization, thermal deterioration of the paste resin, and the like, resulting in a decrease in heat dissipation.

In recent years, as a lead-free solder, research and development of a solder alloy containing tin as a main component, which has a high heat dissipation property, has been advanced. However, until now, solder alloys containing tin as a main component have not yet achieved sufficient reliability.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a bonding material made of a solder alloy containing tin as a main component, which has high heat dissipation and high reliability.

In order to solve the above-mentioned problems, a bonding material according to the present invention contains 0.1 wt % or more and 30 wt % or less of at least one element capable of forming a compound with tin and carbon, and contains tin as the main component of the balance.

As used herein, "at least one element capable of forming a compound with tin and carbon (compound-forming element)" refers to any element that forms a compound with tin and carbon. When there are two or more types of compound-forming elements, the content (wt%) of the compound-forming elements in the bonding material is the weight of the two or more types of compound-forming elements contained in the bonding material with respect to the total weight of the bonding material. It shows the ratio of the sum of

As used herein, the term “main component” means an element having the highest abundance ratio among the elements contained in the bonding material.

Moreover, in the bonding material of one embodiment, the compound-forming element includes at least one of titanium, zirconium, and vanadium.

A semiconductor device is provided by bonding a light-emitting element and a base using the bonding material of the above-described embodiment in the method of manufacturing a bonded body of one embodiment.

According to the bonding material of the present invention, a light emitting element can be bonded to a carbon base with high thermal conductivity. In addition, it is possible to provide a semiconductor device capable of ensuring high heat dissipation by maintaining high thermal conductivity due to the high temperature and high humidity resistance of the bonding material.

FIG. 3 is a schematic diagram of one step of the method for manufacturing the semiconductor device according to the first embodiment; FIG. 3 is a schematic diagram of one step of the method for manufacturing the semiconductor device according to the first embodiment; FIG. 3 is a schematic diagram of one step of the method for manufacturing the semiconductor device according to the first embodiment; FIG. 3 is a schematic diagram of one step of the method for manufacturing the semiconductor device according to the first embodiment; FIG. 3 is a schematic diagram of one step of the method for manufacturing the semiconductor device according to the first embodiment; FIG. 3 is a schematic diagram of one step of the method for manufacturing the semiconductor device according to the first embodiment; It is a schematic diagram which installed the semiconductor device on the heat sink. 1 is a schematic diagram of a conventional light-emitting device; FIG.

The bonding material according to the first aspect contains 0.1 wt % or more and 30 wt % or less of at least one element capable of forming a compound with tin and carbon, and the remainder contains tin as a main component.

In the first aspect, the bonding material according to the second aspect may contain the element in an amount of 0.1 wt % or more and 10 wt % or less.

In a bonding material according to a third aspect, in the first or second aspect, the at least one element may be an element that is more easily oxidized than tin.

In a bonding material according to a fourth aspect, in any one of the first to third aspects, the melting point of a compound of the element tin and tin may be 1000° C. or higher.

In a bonding material according to a fifth aspect, in any one of the first to fifth aspects, the at least one element may include at least one selected from the group consisting of titanium, zirconium, and vanadium.

A method for manufacturing a semiconductor device according to a sixth aspect uses the bonding material of any one of the first to fifth aspects,
A semiconductor device is manufactured by bonding the light emitting element and the carbon base.

A semiconductor device according to a seventh aspect comprises a light emitting element,
a carbon base;
the bonding material according to any one of the first to fifth modes for bonding the light emitting element and the carbon base;
including.

A bonding material according to an eighth aspect, in the above first aspect, may contain the element higher than 5 wt % and not higher than 10 wt %.

A bonding material according to an embodiment will be described below with reference to the accompanying drawings. In addition, the same code|symbol is attached|subjected about the substantially same member in drawing.

(Embodiment 1)
<Bonding material>
The bonding material according to Embodiment 1 is an alloy containing 0.1 wt % or more and 30 wt % or less of an element capable of forming a compound with tin and carbon (compound-forming element) and containing tin as the main component of the balance.
The compound-forming element is not particularly limited as long as it forms a compound with tin and carbon and is more easily oxidized than tin.
Table 1 is a table of examples of compounds with tin, carbon, and oxygen of each element, which are compound-forming elements, and standard Gibbs energies of formation of oxides. Note that the chemical formulas of the compounds are examples and do not represent all compounds.

As shown in Table 1, elements capable of forming compounds with tin and carbon ("compound-forming elements") include, for example, Ti, Y, Nb, Pr, La, V, Mn, Th, Fe, Zr, Mo and Li are mentioned. These elements form compounds with both tin and carbon and are more likely than tin to form oxides even when present with tin because the standard Gibbs energy of formation of the oxides is lower than that of tin. The compound-forming element may contain at least one selected from the group consisting of titanium, zirconium, and vanadium.
Here, the reason why titanium, zirconium and vanadium are selected is that their compounds with Sn have high melting points, as shown in Table 1 (addition of melting points). The higher the melting point, the longer the strength of the bonding material is retained. At least, the compound should have a melting point of 1000° C. or higher.
In addition, since the content of the compound-forming element in the bonding material is 0.1 wt% or more, a sufficient amount of the compound is formed at the interface between the bonding material and the carbon base, and the carbon base and the bonding material A good bonding layer having high strength can be formed at the interface between the
The content of the compound-forming element may be higher than 5 wt%. When the content is higher than 5 wt %, the alloy layer grows and stronger joining is possible.

In addition, since the content of the compound-forming element in the bonding material is 30 wt% or less, tin, which is a liquid phase component, remains and wets and spreads on the carbon base during heating when the bonding material and the carbon base are bonded. This results in good bonding without voids.
The content of the compound-forming element is preferably 10 wt % or less.

Further, the remainder of the bonding material may consist solely of tin. At this time, if the bonding material contains only one type of compound-forming element, the bonding material is a binary alloy composed of one type of compound-forming element and tin as a main component.

Also, the remainder of the bonding material may consist of a plurality of elements including tin as a main component. At this time, the bonding material is a multicomponent alloy composed of a compound-forming element and a plurality of elements including tin as a main component.
The content of elements that form compounds with both tin and carbon (compound-forming elements) and other elements other than tin, which is the main component, is preferably 0.01 wt% or less, and more preferably 0.005 wt% or less. good. Moreover, it is preferable that the number of elements that form compounds with both tin and carbon (compound-forming elements) is one.

<Light emitting element>
For example, a general gallium nitride diode can be used as the light emitting element. For example, an n-type nitride rim and p-type gallium nitride are formed on the upper surface of a sapphire substrate, and a p-type electrode and an n-type electrode are formed on the upper surface to enable electrical connection with wires. The bottom surface of the sapphire substrate is metallized (formed with a metal layer) to allow connection with the bonding material. The metallization forms gold for oxidation protection after applying nickel. Note that the metallization may be any element as long as it forms an alloy layer with tin of the bonding material.

<Carbon base>
As the carbon base, a base obtained by forming carbon powder with a molding machine and baking it was used. The carbon powder is aligned by molding, and the thermal conductivity in the thickness direction of the carbon base is 600 W/m·K, and the thermal conductivity in the planar direction is 200 W/m·K.

<Process>
A bonded body and a manufacturing method thereof according to Embodiment 1 will be described below with reference to the drawings. 1A to 1F are schematic diagrams of each step of the method for manufacturing a semiconductor device according to the first embodiment.

(1) First, as shown in FIG. 1A, a bonding material 101 and a carbon base 102 are prepared and bonded. The bonding conditions are as follows. First, the bonding material 101 and the carbon base 102 are placed in a nitrogen atmosphere furnace and heated to 1200° C. at a rate of temperature increase of 50° C./min. As a result, a carbon bonding layer 103 is formed at the interface between the bonding material 101 and the carbon base 102, as shown in FIG. 1B. The carbon bonding layer 103 contains a compound-forming element that forms a compound with both tin and carbon, thereby firmly bonding.
(2) Next, an electrode layer 104 is formed as shown in FIG. 1C. The electrode layer 104 was formed for electrical connection of light emitting elements to be joined later. The electrode layer 104 is adhered to the carbon base 102 by an insulating adhesive layer 105 .

(3) Next, as shown in FIG. 1D, the light emitting element 106 is bonded. Conditions for bonding the light emitting element 106 and the bonding material 101 are as follows. First, the light-emitting element 106 and the carbon base 102 in the state of FIG. 1C are placed in a nitrogen atmosphere furnace, and heated to 350° C. at a rate of temperature increase of 50° C./min. Next, the internal pressure is reduced to 10 Pa during heating, voids are removed, and then the pressure is returned to the atmospheric pressure and cooled. As described above, the light emitting element 106 and the bonding material 101 are bonded.
At the interface between the bonding material 101 and the light emitting element 106 after bonding, a nickel/tin light emitting element bonding layer 107 formed by reaction between the nickel/gold layer metallized on the back surface of the light emitting element 106 and the tin of the bonding material 101 is formed. formed.
(4) Next, as shown in FIG. 1E, the P-type electrode and the N-type electrode of the light emitting element 106 are connected to the electrode layer 104 with a wire 108 .
(5) Next, as shown in FIG. 1F, the semiconductor device 110 is manufactured by sealing the light emitting element 106 with a sealing resin 109 .

Conjugates of the present disclosure were made as shown in Examples 1-12 below. Table 2 shows the production conditions and evaluation results.

As the bonding material 101, a tin-titanium alloy containing 0.1 wt % of titanium and the balance of tin was used. The bonding material 101 is in the form of a molded body with a size of 1 mm×1 mm and a thickness of 0.2 mm. The carbon base 102 used had a size of 4 mm×4 mm and a thickness of 1 mm.
Using this bonding material, a semiconductor device was manufactured as follows.
(1) The bonding material 101 was placed on the carbon base 102 , heated to 1200° C. in a furnace, and cooled to bond the bonding material 101 to the carbon base 102 with the carbon bonding layer 103 .
(2) Next, an electrode layer 104 was formed on the carbon base 102 with an adhesive layer 105 interposed therebetween. The electrode layer was made of Cu and had a size of 1 mm×2 mm and a thickness of 0.05 mm.
(3) After forming the electrode layer 104, the light emitting element 106 having a size of 1 mm×1 mm and a thickness of 0.1 mm was placed on the bonding material 101, and heated and cooled at 350° C. in a furnace to bond.
(4) Next, the light emitting element 106 and the electrode layer 104 were electrically connected by wiring aluminum wires 108 .
(5) After that, the light-emitting element 106 was sealed with the sealing resin 109 to fabricate the semiconductor device 110 .

The manufactured semiconductor device 110 was first left for 3000 hours in a thermo-hygrostat at a temperature of 85° C. and a humidity of 85% in order to confirm the heat radiation property after the reliability test.

<Evaluation method>
After that, as shown in FIG. 2, the semiconductor device 110 is set on the heat dissipation plate 201 and energized to emit light. Temperature measurements were taken.
It can be seen that when the temperature of the surface of the sealing resin 109 is high, heat does not escape from the lower surface of the light emitting element 106 and accumulates.

As the bonding material 101, a tin-titanium alloy containing 1 wt % of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

As the bonding material 101, a tin-titanium alloy containing 10 wt % of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

As the bonding material 101, a tin-titanium alloy containing 15 wt % of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

As the bonding material 101, a tin-titanium alloy containing 30% by weight of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

As the bonding material 101, a tin-vanadium alloy containing 0.1 wt % of vanadium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

As the bonding material 101, a tin-vanadium alloy containing 30 wt % of vanadium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

As the bonding material 101, a tin-zirconium alloy containing 0.1 wt % of zirconium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

As the bonding material 101, a tin-zirconium alloy containing 30 wt % of zirconium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

Comparative example 1

As the bonding material, a tin-titanium alloy containing 0.01 wt % of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

Comparative example 2

As the bonding material, a tin-titanium alloy containing 35 wt % of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

Comparative example 3

As the bonding material, a tin-vanadium alloy containing 0.01 wt % of vanadium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

Comparative example 4

As the bonding material, a tin-vanadium alloy containing 35 wt % of vanadium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

Comparative example 5

As the bonding material, a tin-titanium alloy containing 0.01 wt % of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

Comparative example 6

As the bonding material, a tin-titanium alloy containing 35 wt % of titanium and the balance of tin was used. A semiconductor device was manufactured under the same conditions as in Example 1 except for the above conditions, and the temperature was measured after being left for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%.

Comparative example 7

A silver paste was used as the bonding material. The carbon base 102 used had a size of 4 mm×4 mm and a thickness of 1 mm.
(1) Silver paste was applied to the carbon base 102 with a thickness of 0.1 mm and a size of 1×1, and the light-emitting element was placed on the applied silver paste, which was cured in an air atmosphere at 100° C. for 1 hour to be bonded.
(2) Next, an electrode layer was formed on the carbon base via an adhesive layer. The electrode layer was made of Cu and had a size of 1 mm×2 mm and a thickness of 0.05 mm.
(3) Next, electrical connection was established by wiring an aluminum wire between the light emitting element and the electrode layer.
(4) After that, the light emitting element was sealed with a sealing resin to fabricate a semiconductor device.
In order to confirm the heat dissipation property after the reliability test, the fabricated semiconductor device was first left in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85% for 3000 hours, and the temperature was measured at the same locations as in Example 1. rice field.

<Results and discussion>
Table 2 shows the production conditions, temperature measurement results, and judgment results of Examples 1 to 9 and Comparative Examples 1 to 6.
The evaluation results are: ⊚ because the decrease in luminance is very small at 80° C. or less; ◯ because there is little decrease in luminance from 100° C. or lower to 80° C.; x.

In Examples 1 to 3, the temperatures were as low as 70° C., 75° C., and 80° C., and the judgment was ⊚. This is estimated as follows. First, a tin-titanium-carbon compound is formed as the carbon bonding layer 103 on the interface between the carbon base 102 and the bonding material, and a nickel-tin compound is also formed on the interface between the light-emitting element 106 and the bonding material 101 to bond the light-emitting element. It is believed to be formed as layer 107 . For this reason, unlike adhesion, the thermal resistance of the interface is reduced, the heat of the light emitting element 106 can be efficiently transmitted to the carbon base 102, and furthermore, the heat can escape from the carbon base 102, which has high thermal conductivity, to the heat sink 201. presumed to be

In Examples 4 and 5, the temperatures were 89° C., 97° C. and 100° C. or less, and the judgment was ◯.
In this case as well, heat is released in the same way as before, but since the content of titanium, which has a thermal conductivity of 20 W/m·K, increased compared to the thermal conductivity of tin, which is 50 W/m·K, Compared with 3, it is considered that the cooling performance is slightly lowered.

Similarly, in Examples 6 and 8 using vanadium and zirconium as compound-forming elements, the temperatures were as low as 69° C. and 70° C., and the evaluation was ⊚. In Example 7.9, the temperatures were 95° C., 96° C. and 100° C. or less, and the judgment was ◯.

It can be seen from these results that heat is efficiently released to the carbon base 102 by forming a compound, as in the case of adding titanium as a compound-forming element. On the other hand, vanadium has a thermal conductivity of 30 W/m·K, and zirconium has a thermal conductivity of 22.6 W/m·K. It is assumed that

In Comparative Examples 1 to 7, all the temperatures were 100° C. or higher, and the judgment was x. In Comparative Examples 1, 3, and 5, the content of titanium, vanadium, and zirconium, which are compound-forming elements, was as low as 0.01 wt%, and no compound layer was formed at the interface between the carbon base and the bonding material, resulting in poor heat transfer. It is presumed that the temperature did not rise and the temperature rose.

In addition, in Comparative Examples 2 and 4, since the content of titanium, vanadium, and zirconium, which are compound-forming elements, is as high as 30% by weight, the bonding material does not completely melt during bonding of the light emitting element, and voids do not come off. Voids remained in the layer. It is presumed that the gaps acted as thermal resistance and the temperature did not drop.

In Examples 1 to 9 and Comparative Examples 1 to 6, the state of the bonding layer did not change for 3000 hours in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85%. Analysis of the side surface of the bonding material revealed that titanium, vanadium, and zirconium, which are compound-forming elements, were concentrated as oxides to a surface layer of about 100 nm on the side surface. By adding titanium, vanadium, and zirconium, which form oxides more easily than tin (the configuration according to the second aspect), titanium, vanadium, and zirconium migrate to the surface in contact with oxygen, forming a strong oxide layer. It is presumed that by forming as , the intrusion of oxygen above a certain level is suppressed.

However, in Comparative Example 7, since silver paste was used as the bonding material, oxygen and water vapor entered the inside of the resin by leaving it in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85% for 3000 hours, and the resin deteriorated. , voids had occurred. As a result, the thermal conductivity decreased, the temperature increased, and the result was x.

From these results, it can be seen that an alloy containing 0.1 wt % or more and 30 wt % or less of a compound-forming element and containing tin as the main component as the balance is preferable as a bonding material. Moreover, it is preferable to manufacture a semiconductor device by bonding a graphite base and a light emitting element using this bonding material. As a result, when the temperature and humidity are constant, the compound-forming elements of the bonding material are concentrated as oxides at the sealing resin interface on the side surface, functioning as passivation to suppress the progress of oxidation and ensure high reliability. can be done.
From the results of Examples 1 to 3, the concentration of the compound-forming element is preferably 0.1 wt % or more and 10 wt %. This applies not only to Ti but also to V and Zr. This is because Ti, V, and Zr have poorer thermal conductivity than Sn, and if added in large amounts, the thermal characteristics deteriorate.

It should be noted that the present disclosure includes appropriate combinations of any of the various embodiments and / or examples described above, and each embodiment and / or The effects of the embodiment can be obtained.

A semiconductor device composed of a light-emitting element and a carbon base bonded by the bonding material according to the present invention ensures high heat dissipation and high reliability, and can be used even for high-brightness drive currents. is.

101 bonding material 102 carbon base 103 carbon bonding layer 104 electrode layer 105 adhesive layer 106 light emitting element 107 light emitting element bonding layer 108 wire 109 sealing resin 110 semiconductor device 201 heat sink 301 semiconductor device 302 light emitting element 303 base 304 silver paste 305 Electrode 306 Wire 307 Sealing resin

Claims (9)

a semiconductor element that is a member having a metal layer;
a carbon base that is a carbon member;
A bonding material that bonds the semiconductor element and the carbon base,
The bonding material is
0.1 wt% or more and 30 wt% or less of at least one element capable of forming a compound with tin and carbon, and the remainder containing tin as a main component;
near the interface between the carbon base and the bonding material, the tin, the carbon base, and the at least one element form a compound;
A semiconductor device , wherein the metal layer and the tin form a compound near an interface between the metal layer and the bonding material. 2. The semiconductor device according to claim 1, wherein said metal layer contains nickel. 3. The semiconductor device according to claim 1, containing 0.1 wt % or more and 10 wt % or less of said element. 4. The semiconductor device according to claim 1, wherein said at least one element is an element that is more easily oxidized than tin. 5. The semiconductor device according to claim 1, wherein the compound of said element with tin has a melting point of 1000[deg.] C. or higher. 6. The semiconductor device according to claim 1, wherein said at least one element includes at least one selected from the group consisting of titanium, zirconium and vanadium. The method for manufacturing the semiconductor device according to any one of claims 1 to 6,
A method of manufacturing a semiconductor device, wherein a semiconductor device is manufactured by bonding a light-emitting element, which is a member having the metal layer, and a carbon base, which is the carbon member. 7. The semiconductor device according to claim 1, wherein said semiconductor element is a light emitting element. 7. The semiconductor device according to claim 1, comprising more than 5 wt % and 10 wt % or less of said element.

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